I used a helmet mounted mirror for many years until a low branch wiped it off. It worked, but wasn't great. I kept using it because I figured that all helmet/glasses mirrors were about the same. However, when I replaced it with the "Take A Look" glasses mounted mirror I found it much more stable than the helmet mount - even with the helmet snug there was some vibration. My glasses are snug and the mirror does not move. As Rick said, all you have to do is turn your head a bit to see what you need.